I have had these two male society finches for two and a half years now, and recently one has spent most of the day sitting in the nest, with the other sitting on top of him. It almost looks like the top bird is incubating the one underneath.
Occasionally they will both be out of the nest, normal as can be, eating and drinking, but the rest of the day they sit like that.
At night they sleep as normal, in their nest side by side.